Practice-based research has the potential to dramatically improve the speed, efficiency, relevance, and impact of mental health clinical and services research. Realizing those gains will require a practice-based research network capable of anticipating and adapting to changes in mental health care delivery, including: ? Research fully embedded in real-world practice ? Alignment of research goals with priorities of patient and health system stakeholders ? Large-scale data infrastructure available for rapid analysis ? A culture of trust and transparency to facilitate collaborative learning and improvement We propose to expand the existing Mental Health Research Network (MHRN) to include 14 research centers embedded in health systems serving a combined population of over 25 million patients in 16 states. MHRN infrastructure will be enhanced to support a next-generation practice-based network, including: ? Increased engagement of patients, health system leaders, and other stakeholders in network governance ? An expanded public, open-source library of software tools and other technical resources ? More formal processes for conducting feasibility pilot projects and rapid response to stakeholder queries ? Expanded outreach to external stakeholders and research partners This Overall application requests support for an Administrative Core, a Methods core, and four research projects. The Administrative Core will support all network activities, including ongoing affiliated research projects, new research projects proposed in this application, and new projects developed during the coming funding cycle. An Organizational Unit will include executive leadership, governance, strategic planning, and responsibility for financial management and regulatory compliance. An Outreach and External Collaboration Unit will be responsible for stakeholder engagement and developing collaborations with new research partners. An Emerging Issues Unit will support timely responses to emerging scientific and public health questions. The Methods Core will support optimal use of existing methods across all network research and develop new methods to address high-priority public health questions. An Informatics Unit will maintain and improve network data infrastructure and disseminate network-developed informatics resources. A Scientific Analysis Unit will focus on improving the methodologic rigor of network projects and development of innovative analytic methods driven by stakeholder needs. These infrastructure resources will support two Signature research projects (a pragmatic trial of eHealth interventions for perinatal depression and a real-time evaluation of new medications to address suicide risk) and two Pilot research projects (an investigation of stakeholder perspectives on implementation of suicide risk prediction models and a pilot trial of outreach to reduce disparities in depression treatment initiation).